The invention concerns a columnar shaped piece comprising a thermoplastic matrix with ancillary pieces of a non-creeping hard material embedded therein and cemented by the plastic matrix.
A columnar shaped piece of the aforesaid type is generally known. The ancillary pieces embedded therein and cemented by the plastic matrix consist of essentially spherical mineral dyes. They provide the piece with color and have only a very slight effect on the piece's mechanical properties, especially its bending resistance.
A method is known for the manufacture of columnar shaped pieces wherein a thermoplastic is melted in an extruder, blended with ancillary pieces of non-creeping material, introduced into a mold and shaped into a piece therein, and solidified by cooling. The ancillary pieces in this method are particles of pigment. They dictate only the color of the resulting columnar-shaped piece.